The ActiveWrap Back Wrap is a low back orthosis designed for use by individuals with back pain or injury. This hot or cold wrap is made to offer full freedom of movement during usage for both adults and youth while providing relief and comfort from muscle, joint, and tendon pain. Each wrap consists of one latex free, non-toxic hot or cold pack in a wrap. The wrap is made of Active Medical Plush with Lycra trim for comfort. Perforated plush-neoprene panels ventilate where heat is not normally needed. The hot and cold packs stay soft during application while non-migrating gel maintains even pressure. SIZES: Extra small, medium (fits waists 34 inches and under), large, and extra extra large (fits waists 35 to 54 inches). DIMENSIONS: The hot/cold pack is 7 x 10 inches. WEIGHT: 1.2 pounds. COLOR: black. WARRANTY/GUARANTEE: 1 year.